a. Field of the Invention
The invention relates to devices for removing snow from driveways; from streets, roads, highways, etc. (hereinafter for simplicity called “roadways”); from all or parts of parking lots; and from sidewalks and other walkways.
b. Description of the Prior Art
Most plows for the removal of snow are mounted on the front of a vehicle. However, snowplows made for attachment to the front of vehicles are very heavy and require much bracket hardware and other complex hardware for controlling and stabilizing purposes. Their weight and rigidity often cause damage to roadway surfaces, curbs, and imbedded reflectors in fog-prone areas. Such snowplows are also very expensive, bulky, and heavy—too much so for the individual householder, the small-business person, the entrepreneur offering light-duty snow removal service, or a teenager seeking after-school or weekend jobs. Such snowplows are difficult to assemble, difficult to attach to vehicles, and, when not needed out of season, difficult to detach and to store. Further, such snowplows are not suited for attaching to ordinary automobiles or other relatively lightweight vehicles, requiring instead some kind of heavy-duty truck.
Modern vehicles are able to travel without difficulty over new-fallen snow, otherwise still-soft snow, or slush several inches deep, even without such enhancing equipment as all-weather tires, four-wheel drive, limited-slip differential, etc. Therefore, if a vehicle can drive over a snow-laden path, a towed snowplow is practicable.
A number of snowplows have been designed for attaching to the rear of vehicles or other means of propulsion. However, they suffer many limitations and disadvantages.
Two of these devices, for example, under U.S. Pat. Nos. 3,800,447 to Harvey and 4,907,357 to Lilienthal are designed not for general removal of snow from a path, but merely to remove snow from a close to a wall or garage door where the vehicle's front-mounted plow cannot each.
In another example, a grading device under U.S. Pat. No. 6,070,343, to Sheldon, intended for grading or snow removal, is to be attached to a towing hitch. Most vehicles are not equipped with or suited for towing hitches. Further, among other disadvantages, the device has no provision for stability in relation to the rear of the vehicle. Differential resistance of snow or some small object encountered on the left side of the device, looking forward, would cause the chain on the right side to collapse and destroy the plow's ability to properly deposit the snow.
Still other devices, such as those under U.S. Pat. Nos. 4,403,432 and 5,595,007 to Biance, and U.S. Pat. Nos. 5,930,922 and 6,151,809 to Altheide require much hardware to control the lifting and aiming of their devices. Such devices are very heavy, probably requiring handling by more than one person, they are time consuming to assemble and disassemble and to attach to and detach from a vehicle. They incur great expense, and they require a large space for storage.
Some snow clearing devices designed to be drawn purport to be snowplows, but are really devices that could be better defined as “scoops” or “gatherers.” For example, see U.S. Pat. No. 79,913 to Lewis, a vee-shaped device intended to clear snow from skating ponds and ice-lakes. Snow is repeatedly gathered inside the vee of the device and hauled to the side of the pond or lake and dumped. Another example occurs in U.S. Pat. No. 235,201 to Bond, whose snow scraping device also is intended to gather snow inside the vee of the device and remove it “from the surface of ice ponds and rivers where ice is to be cut and gathered.”
Features that permit a snowplow to be lifted, manipulated, and carried by one person—light weight, compactness, and handhold devices—are of great importance in a light-duty vehicle-drawn snowplow. Several snowplow devices are purported to have parts that are of lightweight material, but their entire assemblage is not light in weight; for example, see U.S. Pat. No. 4,680,880 to Boneta (which happens to be for a front-loaded device), whose device is composed of many parts, most of them of heavy steel. In some cases, even if the device has some lightweight elements, the entire assemblage is both heavy and composed of multiple units impossible to lift and handle together; for example, see U.S. Pat. No. 1,393,724 to Lackie).
The blades of some snowplows have been fitted with replaceable wear strips, designed to prolong the life of the blades used for heavy-duty service. Examples are the snowplow under U.S. Pat. No. 1,811,436 to Luyster, which has steel wear strips fitted to wooden blades, and the moldboard for a snowplow under U.S. Pat. No. 3,477,149 to Wagner, which has very hard polyurethane rubber, on the order of 85 Durometer (that is, somewhere between the hardness of shoe heels and bowling balls). While these very hard, inflexible wear strips may serve their purpose to prolong blade life, they fail to address the problem of providing a cleaner removal of snow from surfaces that are uneven.
The methods used to vary the widths of various vee-shaped snowplows that have been patented are more cumbersome and time-consuming than necessary. For example, U.S. Pat. No. 509,811 to Jones discloses a hand-pushed snowplow whose width is varied by attaching a crossbar at varying points on both blades of the plow, a procedure that can be improved upon. In another example, under U.S. Pat. No. 1,811,436 to Luyster, varying the width of the snowplow is accomplished by using an adjustable crossbar consisting of a pipe within a pipe set at different lengths by use of a pin through holes in the pipes. It is not made clear how the pin is made secure, but it probably calls for some manipulation. This method is also one that can be improved upon.
A vee-shaped snowplow that is intended to be disassembled for storage or transportation needs a simple, uncomplicated, and inexpensive means of attaching and detaching its blades to and from each other at the vee point. An example of a vee-point that does not meet these criteria is shown in U.S. Pat. No. 509,811 to Jones, which calls for the manufacture and assembling of a completely separate vee-point unit, consisting of several parts. Another example of a device that fails to meet these criteria is shown in U.S. Pat. No. 1,811,436 to Luyster, which also calls for the manufacture and assembling of a complex multiplicity of parts. Still another example of a device that fails to meet these criteria is shown in U.S. Pat. No. 1,393,724 to Lackie, whose hinge is undoubtedly of the conventional kind having two plates with several knuckles, which requires two hands to exactly line up and hold the knuckles in place, and requires a third hand to insert a pin through the knuckles.
What is needed and not provided in the prior art is an effective snowplow with a minimum number of parts; that does not require attaching to a trailer hitch or other special hardware on the towing vehicle; that is simple and inexpensive to manufacture and sell; that is compact for shipping, transporting, and storing; that is lightweight and compact enough to be handled by one person, adult or teenager; that can be easily and quickly assembled and disassembled by one person; that can be easily and quickly attached to and detached from a vehicle; that does not require cumbersome and unsightly hardware on the towing vehicle; that is simple and efficient to operate; that is stable in use; that is as easily adjustable in width as possible; that can easily be adjusted to deposit snow on either or both sides of the path being plowed; that has provision for cleaning uneven surfaces; that requires very little propulsive power; that can overcome unusual or unexpected minor obstructions in the path being plowed; that is durable; and that will rarely, if ever, need repair.
The present invention addresses all of the limitations and problems found in the prior art, and it is designed to fulfill all of the criteria listed in the preceding paragraph.